A study examining the environmental consequences of consuming potatoes grown in GB compared with other carbohydrates has shown that up to the point of retail, a portion of potatoes has a potentially lower environmental impact than basmati rice or pasta. The detailed findings were presented to a group of levy payers and other key stakeholders at a Potato Council briefing recently.
Explaining the parameters of the study, principal research fellow from Cranfield University, Dr Adrian Williams, said: “We looked at British grown white potatoes, Indian basmati rice and Italian pasta and explored two environmental indicators: greenhouse gas emissions (GHGE) and the potential impact on water scarcity, up to the point of delivery at the retailer. Our results showed that on both a dry and fresh weight basis, Indian basmati rice has the highest greenhouse gas emissions and potential impact on water scarcity of the three carbohydrates.
“On a dry weight basis, there is no statistically significant difference between the GHGE of pasta and potatoes but the value for basmati rice is around double that of the others. That can largely be attributed to greater GHGE at the primary production stage for rice and also increased emissions relating to the greater distances involved in transporting the product to regional distribution centres. Pasta has greater emissions associated with processing than potatoes, but potatoes have emissions associated with storage and transport and these cancel each other out.”
The potential impact on water scarcity was measured on the consumption of ‘blue’ water; water which, is withdrawn from surface and groundwater resources. This is then scaled by a factor that balances the local water supply and demand.
The study revealed that the amount of blue water consumed in the production of 1 kg of fresh weight basmati rice in around 100 times the amount used to produce either British potatoes or Italian pasta. Italian pasta has three times the potential impact on water scarcity compared with British potatoes on a fresh weight basis.
Dr Williams explained: “In all three cases, most of the blue water consumption is associated with the cultivation of the crop and used for irrigation. The main difference between the three carbohydrates is that Indian rice is fully irrigated in the early part of cultivation, whereas only part of the British potato and Italian durum wheat crop is irrigated to supplement rainfall.
“The estimates of blue water consumption have been weighted according to the degree of water stress in the region. So although the amount of water consumed in processing basmati rice is in fact very small compared with water used to grow the crop, because it is geographically more localised it can have a significant impact on water resources.”
In conclusion, the study showed that a portion of potatoes has the lowest impact on greenhouse gas emissions and water scarcity, with 30% of the impact on GHGE and 1% of the potential impact on water scarcity, compared to a portion of Indian basmati rice. When compared to a portion of Italian pasta, the figures are 46% and 65% respectively.
Dr Williams said: “Although further environmental losses may occur in retail or in the home, the study clearly shows that up to the point of retail, a portion of potatoes has a potentially lower environmental impact than basmati rice or pasta.”
Potato Council’s head of marketing and corporate affairs, Caroline Evans, said: “Not only are potatoes nutritionally more beneficial than rice or pasta, we now have the evidence to show that they are also more sustainable than alternative carbohydrates by portion size. This is a really positive message for our industry and our focus now will be on working together to communicate these messages to Government and other key stakeholders, as well as to consumers.”
